"Trevor Wilson" wrote in
message



**Er, not quite. The FR plots of MC carts, in some cases,
CAN be shown to be superior.

In some cases the FR of MM cartriges are at worst the equal.

No, the true hard parameter in the design of a cartridge is the moving mass,
not the inductance of its pickup coils. Less moving mass for a given amount
of brute force strength, the greater the potential of the design.

Brute force strength is an important parameter of a cartrdige for two main
reasons:

(1) Durabilty.
(2) Ability to tracking the rapid undulations of the LP groove.

The beauty of the MM design is that the moving magnet can be structural as
well as being the primary signal generating element. With modern
high-energy magnetic materials the magnetic generating element can be made
as virtually as small as is desired.

A moving coil cartridge's coils can't be as strong of a structural element.
The coils work best if there is also a moving magnetic core. This adds up to
excess weight. Furthermore it is far more difficult to make small coils of
wire and wire leads to transmit the signal, as opposed to simple small
blocks of solid magnetic material that itself has considerable inherent
strength.

The reason, of course, is
blindingly simple. It's all about inductance. The
inductance of (LOW OUTPUT) MC carts is very low, indeed.

The inductance of a MC cartrridge is irrelevant because it can be made to be
whatever is desired. The cost of reducing it is reduced output, but that is
pretty much a given with MC cartridges.

The inductance of a coil is proportional to the square of the number of
turns. The output voltage of a coil in a varying magnetic field is
proportional to the number of turns. Thus, if a cartridge is allowed to have
a mere 3 dB less output, it has half the inductance.

In fact the inductance of MM cartridges is optimized to provide smooth
response, not minimize inductance. Fools that they are, designers of MM
cartrdiges tend to be most interested in high fidelity.

This enables them to produce a very flat, very wide (up
to around 60kHz) frequency response, with a
correspondingly superior rise time.

All of which are well-known to have zero audible benefits.

The real benefit of
such a system is that LC resonance effects are often well
outside the audible range.

Ignores the fact that the resonance that actually dictates the response of a
cartridge in ways that can't be managed is the resonance between the moving
mass of the cartridge stylus and paraphenalia that is attached to it, and
the compliance of the vinyl.

This means that a low output
MC cart may exhibit a very flat phase response within the
audio band.

Which is again well-known to have zero audible benefits.

This may not be the case with high output MC
carts nor with some MM carts.

For the record: Many, well designed, MM carts do not
exhibit any resonance problems without the audio band.

Thus invalidating Trevor's entire argument.